关键词: 水土流失, 南京市, “3S”技术, 定量监测, 降雨侵蚀

Abstract: A set of novel methods quantitatively monitoring soil erosion loss is employed to calculate the soil erosion loss in Nanjing City in 2011-2015 according to data of rainfall, land use, soil and terrain, and environmental satellite. Results revealed that: (1) From 2011 to 2015, the average total amount of soil erosion loss in Nanjing is 2.014 2 million tons, among which above light level (above level II) soil erosion is 1.667 7 million tons, occupying an area of 515.75 km² and accounting for 82.8% of the total amount; soil erosion above level II remains a focus of control work. (2) With rainfall erosivity R_i as a decisive factor, the most severe soil erosion happened in 2015, while the slightest in 2013. (3) The five-year average amount of extremely severe (level VI) and severe (level V) soil erosion ranks top among the grading. (4) Compared with ten-year average in 2001-2010, the area of slight (level I) soil erosion in 2011-2015 increased by 7.6%, while the area of erosion above level II reduced by 42.5%, with the amount cut by 23.7%; the decrease in CP(vegetation cover and preservation measure) is the main cause of such mitigation in 2011-2015. (5) In 2011-2015, the decrease in area and amount of level IV and V alleviated; while the area and amount of level VI exacerbated due to large value of rainfall erosivity R_i (five-year average in 2011-2015). The research achievements offer important fundamental data support and scientific basis for the soil and water conservancy planning and soil erosion control in Nanjing City.

Key words: soil erosion loss, Nanjing City, 3S technology, quantitative monitoring, rainfall erosion